Ball check valve with BSPP threaded connection, ductile cast iron GGG40 housing, NBR seal, steel + NBR ball to prevent liquids or gases from flowing back. The valve thus offers one-way passage. The ball check valve opens as soon as the minimum opening pressure is reached, the internal ball rises as the pressure increases in the pipe. As soon as the pressure decreases, the ball check valve closes by means of the ball. Ball check valves are easy to maintain, because the ball rotates during use and thus cleans itself. Full passage is ensured during low pressure, the risk of dirt accumulation is zero and a tight seal is guaranteed. The ball check valve is suitable for clean water, sewage, viscous liquids and drinking water.